vc4: Emit max number of temps in the shader-db output.

We need to be paying attention to optimization's impact on this -- even if
we reduce instruction count, increasing max temps in general is likely to
cause us to fail to register allocate on some shaders, which means that
those won't run at all.

diff --git a/src/gallium/drivers/vc4/vc4_qir_live_variables.c b/src/gallium/drivers/vc4/vc4_qir_live_variables.c
index 330e1c8..7108b3e 100644 (file)
--- a/src/gallium/drivers/vc4/vc4_qir_live_variables.c
+++ b/src/gallium/drivers/vc4/vc4_qir_live_variables.c
@@ -327,4 +327,27 @@ qir_calculate_live_intervals(struct vc4_compile *c)
                 ;
 
         qir_compute_start_end(c, c->num_temps);
+
+        if (vc4_debug & VC4_DEBUG_SHADERDB) {
+                int last_ip = 0;
+                for (int i = 0; i < c->num_temps; i++)
+                        last_ip = MAX2(last_ip, c->temp_end[i]);
+
+                int reg_pressure = 0;
+                int max_reg_pressure = 0;
+                for (int i = 0; i < last_ip; i++) {
+                        for (int j = 0; j < c->num_temps; j++) {
+                                if (c->temp_start[j] == i)
+                                        reg_pressure++;
+                                if (c->temp_end[j] == i)
+                                        reg_pressure--;
+                        }
+                        max_reg_pressure = MAX2(max_reg_pressure, reg_pressure);
+                }
+
+                fprintf(stderr, "SHADER-DB: %s prog %d/%d: %d max temps\n",
+                        qir_get_stage_name(c->stage),
+                        c->program_id, c->variant_id,
+                        max_reg_pressure);
+        }
 }